Check
the appropriate box to designate the rule pursuant to which this Schedule is filed:

☐ Rule
13d-1(b)

☐ Rule
13d-1(c)

☒ Rule
13d-1(d)

*
The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the
subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in
a prior cover page.

The information required on the
remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange
Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other
provisions of the Act (however, see the Notes).

(ii) Messrs.
Andreas and George Hadjimichael are citizens of the Republic of Cyprus.

(iii)
Messrs. Czernik and Smolokowski are citizens of the Republic of Poland.

(d)

Title
of Class of Securities

Common
Stock

(e)

CUSIP
Number

48576U106

CUSIP
No. 048576U106

13G

Page 8
of 10 pages

Item
3. If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person
filing is a:

Not
applicable.

Item
4. Ownership.

Provide
the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in
Item 1.

(a)

Amount
beneficially owned: 8,549,920 shares.
These shares of Common Stock are owned directly by Chione. Chione's directors, Marcin Czernik, Andreas Hadjimichael and George
Hadjimichael, and its sole stockholder, Wiaczeslaw Smolokowski, may be deemed to share voting and investment power and beneficial
ownership of such shares of Common Stock. Each of such directors and stockholder disclaims such voting and investment power
and beneficial ownership. The number of shares listed on the cover pages of this Schedule 13G pertaining to Chione’s
directors includes the shares of Common Stock owned directly by Chione, but does not include shares of Common Stock owned
directly by Plio Ltd., which has the same directors and as to which each of such directors may be deemed to share voting and
investment power and beneficial ownership. Each of such directors disclaims such voting and investment power and beneficial
ownership.

(b)

Percent
of class: 18.1%. See item 4(a) above.

(c)

Number
of shares as to which the person has:

Chione

(i)
Sole power to vote or to direct the vote 0.

(ii)
Shared power to vote or to direct the vote 8,549,920.

(iii)
Sole power to dispose or to direct the disposition of 0

(iv)
Shared power to dispose or to direct the disposition of 8,549,920

Mr.
Czernik

(i)
Sole power to vote or to direct the vote 0.

(ii)
Shared power to vote or to direct the vote 8,549,920.

(iii)
Sole power to dispose or to direct the disposition of 0

(iv)
Shared power to dispose or to direct the disposition of 8,549,920

Mr.
Andreas Hadjimichael

(i)
Sole power to vote or to direct the vote 0.

(ii)
Shared power to vote or to direct the vote 8,549,920.

(iii)
Sole power to dispose or to direct the disposition of 0

(iv)
Shared power to dispose or to direct the disposition of 8,549,920

CUSIP
No. 048576U106

13G

Page 9
of 10 pages

Mr.
George Hadjmichael

(i)
Sole power to vote or to direct the vote 0.

(ii)
Shared power to vote or to direct the vote 8,549,920.

(iii)
Sole power to dispose or to direct the disposition of 0

(iv)
Shared power to dispose or to direct the disposition of 8,549,920

Mr.
Smolokowski

(i)
Sole power to vote or to direct the vote 0.

(ii)
Shared power to vote or to direct the vote 8,549,920.

(iii)
Sole power to dispose or to direct the disposition of 0

(iv) Shared
power to dispose or to direct the disposition of 8,549,920

See
item 4(a) above.

Item
5. Ownership of Five Percent or Less of a Class.

Not
applicable.

Item
6. Ownership of More than Five Percent on Behalf of Another Person.

Not
applicable.

Item
7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent
Holding Company.

Not
applicable.

Item
8. Identification and Classification of Members of the Group.

Not
applicable.

Item
9. Notice of Dissolution of Group.

Not
applicable.

Item
10. Certification.

Not
applicable.

CUSIP
No. 048576U106

13G

Page 10
of 10 pages

After
reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true,
complete and correct.

The undersigned, Marcin Czernik, hereby
appoints Simon Prisk as his attorney-in-fact (i) for and on behalf of the undersigned, including, without limitation, in my current
or future capacity as a director and, if applicable, as an officer of Chione Limited (the “Company”), and (ii) for
and on behalf of the Company, in each case, in respect of (A) any current or future direct or indirect beneficial ownership of,
or pecuniary interest in (whether or not such beneficial ownership or pecuniary interest is disclaimed), securities of Karyopharm
Therapeutics Inc., including any successor entity (“KTI”), and (B) any other status or transaction of or involving
the undersigned and/or the Company requiring any filing or report pursuant to the Securities Exchange Act of 1934 and the rules
and regulations thereunder or applicable thereto (the “Exchange Act”) in respect of such securities, including, without
limitation, pursuant to Section 13 or 16 of the Exchange Act. Such appointment as attorney-in-fact shall include, without limitation,
the power and authority:

1.

to execute and file a Form ID on behalf of the undersigned and otherwise to secure any codes required
in order for the undersigned
to be able to file with the U.S. Securities and Exchange Commission’s Edgar system;

2.

to execute and file any Form 3, Form 4, or Form 5, Schedule 13G or 13D, any amendments
to any such Form or Schedule, and any filing agreements related to securities of KTI on behalf of the undersigned and/or the Company;

3.

to seek and obtain information on behalf of, and as the representative of the undersigned and/or
the Company, from any and all persons, including, without limitation, representatives of the Company and KTI, in connection with
the foregoing; and

4.

to do and perform any and all acts and things, including, without limitation, to execute, submit
and file such agreements, instruments, forms and other documents, to incur such expenses, as may be necessary or desirable, in
the sole discretion of such attorney-in-fact, in connection with the foregoing, it being understood that the documents executed
by such attorney-in-fact pursuant to this Limited Power of Attorney shall be in such form and shall contain such information as
such attorney-in-fact may approve in such attorney-in-fact’s sole discretion.

The undersigned acknowledges that said
attorney-in-fact is not assuming any of my responsibilities to comply with the Exchange Act.

Said attorney-in-fact may (i) act in reliance
upon the signature below; and (ii) assume that any person, whether as an individual or as a person who has been designated by the
Company or KTI or any other person to give any written instructions, notice or receipt, or make any statements in connection with
the foregoing matters (or any of them) has been duly authorized to do so.

Said attorney-in-fact shall have no duty
to make inquiry as to the genuineness, accuracy or validity of any statements or instructions or any signatures or instructions.

This Limited Power of Attorney will remain
in effect until February 2, 2019 or until such earlier time as a written revocation of this Limited Power of Attorney is delivered
to said attorney-in-fact at the then current address of the Ruchelman Law Firm.

The undersigned is signing this Limited Power of Attorney as
of February 2, 2018.

/s/ Marcin Czernik

Marcin Czernik, individually, including in his capacity as an officer and/or director of the Company (as applicable), and on behalf of the Company

Exhibit 24.2

LIMITED POWER OF ATTORNEY

The undersigned, Andreas Hadjimichael,
hereby appoints Simon Prisk as his attorney-in-fact (i) for and on behalf of the undersigned, including, without limitation, in
my current or future capacity as a director and, if applicable, as an officer of Chione Limited (the “Company”), and
(ii) for and on behalf of the Company, in each case, in respect of (A) any current or future direct or indirect beneficial ownership
of, or pecuniary interest in (whether or not such beneficial ownership or pecuniary interest is disclaimed), securities of Karyopharm
Therapeutics Inc., including any successor entity (“KTI”), and (B) any other status or transaction of or involving
the undersigned and/or the Company requiring any filing or report pursuant to the Securities Exchange Act of 1934 and the rules
and regulations thereunder or applicable thereto (the “Exchange Act”) in respect of such securities, including, without
limitation, pursuant to Section 13 or 16 of the Exchange Act. Such appointment as attorney-in-fact shall include, without limitation,
the power and authority:

1.

to execute and file a Form ID on behalf of the undersigned and otherwise to secure any codes required
in order for the undersigned
to be able to file with the U.S. Securities and Exchange Commission’s Edgar system;

2.

to execute and file any Form 3, Form 4, or Form 5, Schedule 13G or 13D, any amendments
to any such Form or Schedule, and any filing agreements related to securities of KTI on behalf of the undersigned and/or the Company;

3.

to seek and obtain information on behalf of, and as the representative of the undersigned and/or
the Company, from any and all persons, including, without limitation, representatives of the Company and KTI, in connection with
the foregoing; and

4.

to do and perform any and all acts and things, including, without limitation, to execute, submit
and file such agreements, instruments, forms and other documents, to incur such expenses, as may be necessary or desirable, in
the sole discretion of such attorney-in-fact, in connection with the foregoing, it being understood that the documents executed
by such attorney-in-fact pursuant to this Limited Power of Attorney shall be in such form and shall contain such information as
such attorney-in-fact may approve in such attorney-in-fact’s sole discretion.

The undersigned acknowledges that said
attorney-in-fact is not assuming any of my responsibilities to comply with the Exchange Act.

Said attorney-in-fact may (i) act in reliance
upon the signature below; and (ii) assume that any person, whether as an individual or as a person who has been designated by the
Company or KTI or any other person to give any written instructions, notice or receipt, or make any statements in connection with
the foregoing matters (or any of them) has been duly authorized to do so.

Said attorney-in-fact shall have no duty
to make inquiry as to the genuineness, accuracy or validity of any statements or instructions or any signatures or instructions.

This Limited Power of Attorney will
remain in effect until February 2, 2019 or until such earlier time as a written revocation of this Limited Power of Attorney
is delivered to said attorney-in-fact at the then current address of the Ruchelman Law Firm.

The undersigned is signing this Limited Power of Attorney as
of February 2, 2018.

/s/ Andreas Hadjimichael

Andreas Hadjimichael, individually, including in his capacity as an officer and/or director of the Company (as applicable), and on behalf of the Company

Exhibit 24.3

LIMITED POWER OF ATTORNEY

The undersigned, George Hadjimichael, hereby
appoints Simon Prisk as his attorney-in-fact (i) for and on behalf of the undersigned, including, without limitation, in my current
or future capacity as a director and, if applicable, as an officer of Chione Limited (the “Company”), and (ii) for
and on behalf of the Company, in each case, in respect of (A) any current or future direct or indirect beneficial ownership of,
or pecuniary interest in (whether or not such beneficial ownership or pecuniary interest is disclaimed), securities of Karyopharm
Therapeutics Inc., including any successor entity (“KTI”), and (B) any other status or transaction of or involving
the undersigned and/or the Company requiring any filing or report pursuant to the Securities Exchange Act of 1934 and the rules
and regulations thereunder or applicable thereto (the “Exchange Act”) in respect of such securities, including, without
limitation, pursuant to Section 13 or 16 of the Exchange Act. Such appointment as attorney-in-fact shall include, without limitation,
the power and authority:

1.

to execute and file a Form ID on behalf of the undersigned and otherwise to secure any codes required
in order for the undersigned
to be able to file with the U.S. Securities and Exchange Commission’s Edgar system;

2.

to execute and file any Form 3, Form 4, or Form 5, Schedule 13G or 13D, any amendments
to any such Form or Schedule, and any filing agreements related to securities of KTI on behalf of the undersigned and/or the Company;

3.

to seek and obtain information on behalf of, and as the representative of the undersigned and/or
the Company, from any and all persons, including, without limitation, representatives of the Company and KTI, in connection with
the foregoing; and

4.

to do and perform any and all acts and things, including, without limitation, to execute, submit
and file such agreements, instruments, forms and other documents, to incur such expenses, as may be necessary or desirable, in
the sole discretion of such attorney-in-fact, in connection with the foregoing, it being understood that the documents executed
by such attorney-in-fact pursuant to this Limited Power of Attorney shall be in such form and shall contain such information as
such attorney-in-fact may approve in such attorney-in-fact’s sole discretion.

The undersigned acknowledges that said
attorney-in-fact is not assuming any of my responsibilities to comply with the Exchange Act.

Said attorney-in-fact may (i) act in reliance
upon the signature below; and (ii) assume that any person, whether as an individual or as a person who has been designated by the
Company or KTI or any other person to give any written instructions, notice or receipt, or make any statements in connection with
the foregoing matters (or any of them) has been duly authorized to do so.

Said attorney-in-fact shall have no duty
to make inquiry as to the genuineness, accuracy or validity of any statements or instructions or any signatures or instructions.

This Limited Power of Attorney will remain
in effect until February 2, 2019 or until such earlier time as a written revocation of this Limited Power of Attorney is delivered
to said attorney-in-fact at the then current address of the Ruchelman Law Firm.

The undersigned is signing this Limited Power of Attorney as
of February 2, 2018.

/s/ George Hadjimichael

George Hadjimichael, individually, including in his capacity as an officer and/or director of the Company (as applicable), and on behalf of the Company

Exhibit 24.4

LIMITED POWER OF ATTORNEY

The undersigned, Wiaczeslaw Smolokowski,
hereby appoints Simon Prisk as his attorney-in-fact for and on behalf of the undersigned, in respect of (A) any current or future
direct or indirect beneficial ownership of, or pecuniary interest in (whether or not such beneficial ownership or pecuniary interest
is disclaimed), securities of Karyopharm Therapeutics Inc., including any successor entity (“KTI”), and (B) any other
status, including, if applicable, as an officer or director of Chione Limited (the “Company”), or transaction of or
involving the undersigned and/or the Company requiring any filing or report pursuant to the Securities Exchange Act of 1934 and
the rules and regulations thereunder or applicable thereto (the “Exchange Act”) in respect of such securities, including,
without limitation, pursuant to Section 13 or 16 of the Exchange Act. Such appointment as attorney-in-fact shall include, without
limitation, the power and authority:

1.

to execute and file a Form ID on behalf of the undersigned and otherwise to secure any codes required
in order for the undersigned to be able to file with the U.S. Securities and Exchange Commission’s Edgar system;

2.

to execute and file
any Form 3, Form 4, or Form 5, Schedule 13G or 13D, any amendments
to any such Form or Schedule, and any filing agreements related to securities of KTI on behalf of the undersigned and/or the Company;

3.

to seek and obtain information on behalf of, and as the representative of the undersigned and/or
the Company, from any and all persons, including, without limitation, representatives of the Company and KTI, in connection with
the foregoing; and

4.

to do and perform any and all acts and things, including, without limitation, to execute, submit
and file such agreements, instruments, forms and other documents, to incur such expenses, as may be necessary or desirable, in
the sole discretion of such attorney-in-fact, in connection with the foregoing, it being understood that the documents executed
by such attorney-in-fact pursuant to this Limited Power of Attorney shall be in such form and shall contain such information as
such attorney-in-fact may approve in such attorney-in-fact’s sole discretion.

The undersigned acknowledges that said
attorney-in-fact is not assuming any of my responsibilities to comply with the Exchange Act.

Said attorney-in-fact may (i) act in reliance
upon the signature below; and (ii) assume that any person, whether as an individual or as a person who has been designated by the
Company or KTI or any other person to give any written instructions, notice or receipt, or make any statements in connection with
the foregoing matters (or any of them) has been duly authorized to do so.

Said attorney-in-fact shall have no duty
to make inquiry as to the genuineness, accuracy or validity of any statements or instructions or any signatures or instructions.

This Limited Power of Attorney will remain
in effect until February 2, 2019 or until such earlier time as a written revocation of this Limited Power of Attorney is delivered
to said attorney-in-fact at the then current address of the Ruchelman Law Firm.

The undersigned is signing this Limited Power of Attorney as
of February 2, 2018.

/s/ Wiaczeslaw Smolokowski

Wiaczeslaw Smolokowski

Exhibit 99.1

JOINT FILING
AGREEMENT

The
undersigned hereby agree that Amendment No. 3 to the Schedule 13G, dated as of February 12, 2018, with respect to the
Common Stock of Karyopharm Therapeutics Inc. is, and any amendments thereto, any Schedule 13D with respect to such Common
Stock, and any amendments thereto, signed by each of the undersigned shall be, filed on behalf of each of us pursuant to and
in accordance with the provisions of Rule 13d-1(f) under the Securities Exchange Act of 1934.